AU915
Understanding AU915 LoRaWAN Frequency Plan
Australia's vast rural landscape — where cellular coverage is sparse and power infrastructure is limited — is exactly the environment where LoRaWAN excels. The AU915 frequency plan defines how LoRaWAN devices communicate in the 915 MHz ISM band across Australia, enabling long-range IoT connectivity for agricultural monitoring, water management, and remote asset tracking.
Channel Structure
The AU915 plan provides an extensive channel set:
- 64 uplink channels (125 kHz): Spread across the 915–928 MHz band, providing frequency diversity and resistance to narrowband interference.
- 8 uplink channels (500 kHz): For higher data rate transmissions (SF7–SF8 at 500 kHz = up to 21.9 kbps).
- 8 downlink channels (500 kHz): Used by gateways to send data back to devices.
Sub-Band Operation
In practice, many LoRaWAN gateways in the AU915 region listen on only a subset (sub-band) of the 72 uplink channels — typically 8 channels per sub-band — to reduce gateway receiver complexity and cost. Network planning must ensure that devices are configured to transmit on the same sub-band that their nearest gateway is listening on.
Key Equations
AU915 is the regional frequency plan specification for LoRaWAN networks operating in the 915–928 MHz ISM band in Australia and several South American countries (including...
Key specifications:
928 MHz | 125 kHz | 927.8 MHz | 200 kHz | 8 a | 500 kHz
Throughput: R = Nlayers×B×ηSE×(1−OH)
Comparison
| Aspect | AU915 Spec | Typical Range | Impact | Design Note |
|---|---|---|---|---|
| Primary function | AU915 is the regional frequency plan spe... | Application-dep. | Critical | Verify in sim |
| Operating range | Maximum transmit power is limited to 30... | Application-dep. | Critical | Verify in sim |
| Performance | Understanding AU915 LoRaWAN Frequency Pl... | Application-dep. | Critical | Verify in sim |
| Integration | 8 uplink channels (500 kHz): For higher... | Application-dep. | Critical | Verify in sim |
| Trade-off | 8 downlink channels (500 kHz): Used by g... | Application-dep. | Critical | Verify in sim |
Frequently Asked Questions
How does AU915 differ from US902-928?
The channel frequencies and structure are nearly identical — both use the 902–928 MHz ISM band with the same 64+8 uplink and 8 downlink channel arrangement. The differences are regulatory: Australian ACMA regulations specify different maximum EIRP limits, duty cycle requirements, and channel access rules compared to FCC Part 15 regulations in the United States. Devices designed for AU915 operation must be tested and certified against ACMA's Radiocommunications (Low Interference Potential Devices) Class Licence requirements.
What range can AU915 devices achieve?
In the flat, open terrain of rural Australia, LoRaWAN devices operating at SF12 (the slowest, most robust spreading factor) can achieve communication ranges of 15–30 km to a gateway with a well-positioned antenna. In urban environments, range decreases to 2–5 km due to building attenuation and multipath. Gateway antenna height is the single most important factor for maximizing coverage range.
Is the 915 MHz band shared with other services?
Yes, the 915–928 MHz ISM band is shared with many other unlicensed devices including RFID readers, industrial telemetry, and other IoT protocols (Sigfox, Zigbee). LoRaWAN's spread spectrum modulation (chirp spread spectrum) provides inherent interference rejection, but dense deployments must manage coexistence through duty cycle management, listen-before-talk, and frequency hopping across the available channels.